I thought this was PHP related when I started out, but maybe it isn't. My original post, which may be irrelevant now is located at the bottom. I think it should be ignored.

The problem is I have a directory : /articles/. In it are 10 sub directories. I have been changing the permissions lately, but now it seems all the permissions of the parent folder, sub-folders and files are either chmod 755 or 777.

I cannot move, delete or edit files inside of this parent directory or sub-directories with my FTP-client. I can however edit, delete, create new files and directories and change them with PHP-functions without problems.

What may the problem be?

EDIT 3: My hosting company fixed the problem and said it was because of permissions + ownership. I checked these things as thoroughly as I could, so it makes no sense to me, but I suppose they are right.

OLD POST. Ignore everything below this line:

If I create a directory with mkdir(), or create a file with fopen(), file_put_contents() or SimpleXMLElement::asXML(), I am unable to access the file with my FTP-client or c-Panel File Manager.
If I try to delete or edit them, I get errors. Dreamweaver suggests it is a permission problem or a network or filesystem fault (but I've set the permissions with chmod() to 0777, and when I check the cPanel, it confirms chmod 777.
I also tried to use fileowner() and the function returns int(99), the same owner as those files that I could access with my FTP-client.
It seems files and directories created with PHP can only be modified or be deleted with PHP.
I thought this must be a server setup related issue, so I write it here. I am on a shared server, and I have no idea about setting up servers.
EDIT:
It seems the problem is different. I cannot move files with FTP-client to the parent, or sub-directories either. This problem may not be PHP related, then. It seems the problem applies to any directory, regardless of whether it was created by PHP.
EDIT 2: The parent directory has chmod 755.